I recently purchased a deiter CQD grip. It's basically a vertical grip made from aluminum made to fit onto standard 1913 (picatinny rails). I purchased this unit from another user at ar15.com.

I immediately attached it snugly to my rail just a bit forward of center. I don't actually "grip" the rail, but I use it as a stop to rest my hand against to assist in driving the carbine rearward into my shoulder.

I first noticed that what I consider snug for every other accessory wasn't enough for the way this was designed.

FLAW #1:
Should have in spec spacers to assist in grip not being able to be moved forward or backward once attached no matter the screw tension. You're using horizontal pressure to solve a vertical movement problem...I believe the larue FUG has this (which is the closest priced grip to a new deiter CQD)

After this I just turned each hex bolt and extra quarter turn (it has 3 hex bolts). I left it this way for a week or two. As I'm in the phase of rebuilding my whole carbine I started to take it apart. After taking the lower off of the upper, removing my bcg and aimpoint. I got to the point where I would be tapping out the FSB pins, removing that + gas tube and then finally the free float YHM rails and barrel.

So I started to remove the vertical grip first. I started with the middle hex bolt and began to loosen it until I felt all the pressure just instantly go away. I knew what had happened right away...the plate on the other side had stripped.


FLAW #2
The retaining plate is of too soft a metal for the pressures that a "combat" grip may require (taking into consideration FLAW #1 that is).

I contacted deiter about swapping out a retaining plate, but they responded by telling me a new plate was $22 and it would be $7.25 to ship it and that my total cost would come to $29.25. My response was that that was unreasonable because that's half the cost of a grip from other manufacturers (tango down - actually more than half) who will stand behind their product in case of failure. They responded with the "we dont honor warranties beyond the original owner" basically, which is their right to do so. Other manufacturers however do honor and stand behind their products no matter the owner. LaRue is an example of this. Brand new this grip costs $89.99 and I paid $70 for it used. On the MFG site, it's $99.95msrp with it being $91.99 on sale. So in the end I'm basically paying more to have a (properly - to spec) functional used unit. I will claim this issue as my own by not purchasing new though.

Let's take a look at this plate...why would it cost $7.25 to ship it? I recently shipped an AK-47 kit the entire way across the country for $10, which is about 20(guess) times the weight and size of a 1/4" thick, 1/4" tall, 2.5" long piece of aluminum.

FLAW #3
A company that will not stand behind it's product, which is one of the most expensive VFG's on the market (that doesn't have a light built in that is).

So for the moment I'm going to run this thing with two hex bolts holding it on, but I will say that if I am able to sell it and recoup my costs (which will be difficult with a plate with a middle set of threads missing) I will be going to the larue or tango down grips unless deiter decides to respond to my last email (which it's been since wednesday) with an offer to exchange the plate so they can do QA on it.

Pictures of grip, and failure to come.